Technologies have been proposed to defeat or reduce the counterfeiting and parallel importing of products. Most of them contain one or more protection features that are recognizable either by the customer's bare eyes or by a special tool. These measures can be classified into the following types or levels of security. Level 1 involves features that can be recognized overtly with bare eyes of the product's end customers. Technologies such as holograms and marks by optically variable ink (OVI) belong to this group. In the hologram case, one is looking for a specially designed holographic pattern, and in the OVI case the marked pattern will show different colors when being viewed at different angles. Level 2 involves covert or semi-covert features that require a simple and easily obtainable detection device, such as UV/IR (up-conversion) ink in banknotes. In this case one needs only a UV lamp or IR laser pen for verification. When appropriate waveband is illuminated onto the UV/IR ink, it will emit visible light and this can be observed readily by bare eyes. Level 3 involves features that are known only to the brand manufacturer and are verifiable by dedicated tools that cannot be obtained commercially in the market. This kind of authentication method usually requires higher cost of implementation and is not commonly known in the anti-counterfeit market.
The level 1 methods are overtly known by product customers as well as by counterfeiters. They may be easily repeated. The level 2 methods are less obvious and can be hidden in some special area that only manufacturer knows. However once they are known to the counterfeiters, materials with similar characteristics may be readily obtainable in the market, such as common UV/IR security inks. Conventional product authentication methods are mainly level 1 and 2 methods. The methods at level 3 have the highest level of security. First of all, they use special material or blending of materials. Secondly, specially designed analyzing tools are needed for verification. Thirdly, a proprietary algorithm is used for final product authentication which will generally include a confidential database.